<template>
  <div>
    <button @click="addNum">数字自增</button>
    <span v-once>{{ num }}</span>
  </div>
</template>

<script>
export default {
    name:"v_once",
    data(){
        return {
            num:11
        }
    },
methods:{
    addNum(){
        this.num++;
    }
}

}
</script>

<style>

</style>